Structures and properties of carbon-doped amorphous silicon as an anode for lithium ion batteries: a first-principles study

Abstract

Silicon-based materials are considered promising candidates for next-generation lithium-ion battery (LIB) anodes due to their high theoretical specific capacity. However, the significant volume expansion during cycling severely limits their application. In the present study, first-principles calculations were performed to study carbon-doped amorphous silicon as an anode material. Interestingly, the results show that carbon doping in amorphous silicon enhances lithium diffusion, contrary to the effect in carbon-doped crystalline silicon. Further structural analysis revealed that carbon doping increases the disorder of the amorphous network, thereby expanding the lithium-ion diffusion channels.